Botulinum Toxin Testing

The use of natural products as novel therapeutics in medical and cosmetic indications has increased in recent years. One such product is Botulinum toxin, a protein produced by the bacterium Clostridium botulinum that is used to treat muscle spasms, chronic pain, hyperactive nerves, eye muscle disorders and other emerging therapeutic indications.

Botulinum toxin use is highly regulated by both the Food and Drug Administration (FDA) and the Centers for Disease Control (CDC) given its potent biological mechanism of action.

Since 1990, Pacific BioLabs has been working with botulinum toxin developing and offering a variety of in vivo and in vitro testing paradigms in support of research and clinical development efforts by private and commercial entities. Pacific BioLabs is registered, and works closely, with the Federal Select Agent Program at the CDC ensuring compliance with federal regulations associated with handling of botulinum toxin.

Pacific BioLabs has an experienced and dedicated staff with expertise in botulinum toxin testing offering the following assays:

Botulinum Toxin Identity, Dose Concentration Verification and Purity Testing

Pacific BioLabs supports manufacturing related activities for botulinum toxin lot release, which includes identity and dose concentration verification by ELISA and purity testing by SDS-PAGE or HPLC.  Purity, identity and dose concentration verification methods can be validated per both ICH and FDA guidelines.

Botulinum Toxin In Vivo Lot Release Bioassay

Each therapeutic preparation of botulinum toxin is required by the FDA to be tested for potency and stability before being released for use. Pacific BioLabs supports testing of both the active pharmaceutical ingredient (Drug Substance) and the final formulated product (Drug Product) for potency and stability.

BoNT In Vivo and In Vitro Immunogenicity and Nab Assays

Patients undergoing treatment with botulinum toxin may develop antibodies that make the toxin ineffective, or less effective, against the indication for which they are being treated. Therefore, during clinical trials it is required for companies to determine if there is any immunogenicity to their toxin products and if the antibodies produced by the patient neutralize the toxin. For immunogenicity testing, clinical trial serum samples can be submitted to Pacific BioLabs and then tested by ELISA or MSD to determine if there are antibodies against botulinum toxin in the serum.

If there are antibodies produced by the patient, the FDA may require a neutralizing antibody assay be performed. Antibodies that neutralize the toxin will make the toxin ineffective. Pacific BioLabs tests for neutralizing antibodies by injecting the patient serum into a mouse. If a patient has developed botulinum toxin neutralizing antibodies, the assay will show a decrease in toxin activity. PBL only performs immunogenicity and neutralizing antibody assays on clinical trial samples and does not perform this test for physicians or individuals.

BoNT Cell Based Potency Bioassay Development

There is an increased awareness in drug development for the implementation of cell based assays for the determination of botulinum toxin potency, which has already been initiated by several pharmaceutical and biotechnology companies. There are many compelling reasons to develop cell-based assays, not the least of which are high throughput testing and long term cost savings when compared to in vivo testing.  Furthermore, cell based assays have the advantage of evaluating key biological processes that include binding of the toxin to its receptor, internalization-translocation of the receptor and subsequent catalytic activity that may benefit potency optimization efforts that in vivo assays cannot support. Given the extensive experience working with botulinum toxin and bioanalytical expertise, Pacific BioLabs scientists are exploring cell based bioassay methods for botulinum toxin potency determination in order to support customer needs.

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